Deployment of Switched Digital Video (SDV) systems in the cable market has shown that at any given time only 50-60% of the available content line-up needs to be delivered to a service group (e.g. about 1000 set top boxes or STBs). The delivery of content is typically provided via a multicast content delivery stream which includes both content and advertising. Default or network advertising is included within a multicast content delivery stream provided by a content source or network server. Selectively switching between a default advertising portion of the multicast content delivery stream and a local or regional advertising stream is extremely difficult within the context of Internet protocol television (IPTV). This difficulty is increased where the characteristics (e.g., length, bit rate and the like) of the default advertising portion and local/regional advertising streams are different or unknown.